The Effect of H-SAPO-34 Template Type on Conversion of Methanol to Light Olefins

نویسندگان [English]

Laleh Shirazi
1

E. Gangji
1

zahra Taheri
2

1
Gas Research Divisaon, RIPI

2
Chemicstry & Petrochemical Divisaon, RIPI

چکیده [English]

Effects of template type on the catalytic performance of SAPO-34 catalyst in conversion of methanol to light olefins (MTO) have been investigated. SAPO-34 molecular sieves were synthesized by hydrothermal method, using morpholine tetraethyl ammonium hydroxide and dipropylamine as the template in the synthesis of gel with molar composition of Al2O3: P2O5: SiO2: template: H2O being 1:1:0.6:2:50, respectively. The produced samples were characterized by XRD, SEM, NH3-TPD and TGA-DTA techniques. These results showed that template type affects crystal size, morphology, crystallinity and purity of samples. It was found that the average SAPO-34 crystal size increased when morpholine was used as the template. Conversion of methanol to light olefins using acidic SAPO-34 as the reaction catalyst was studied in a fixed bed reactor in the temperature range of 250–450 °C, atmospheric pressure and WHSV=1 hr-1. Although all the catalysts showed similar activity and product distribution, the catalyst obtained using morpholine as the template, had the shortest lifetime.